Generally, wireline and wireless mobile communication systems operate as separate network entities, with wireline and wireless terminal units being addressed by unique directory numbers that are specific to one system or the other. In this configuration, call delivery between systems is performed through static call redirection databases and manual forwarding techniques that are specific to translations, routing and service databases of each particular communication system.
Known systems and call forwarding techniques currently provide a customer with the ability to manually redirect wireline call terminations from their wireline terminal unit directory number to an associated mobile terminal unit. In addition, known systems arrange for the wireline network to query a wireless service provider for availability of an associated mobile terminal unit before redirecting the incoming call to an assigned wireless terminal unit.
In other words, when a call is made to a subscriber's home of office telephone number, the call is delivered by a public switched telephone network (PSTN) to a switch assigned to serve the subscriber's home or office. Upon receipt of the call from the PSTN, the serving switch will execute an AIN Terminating Access Attempt Trigger (TAT) to query an appropriate Service Control Point (SCP) database to obtain special routing instructions. Information contained within the SCP database is used by the wireline switching system to route the call to the subscriber's mobile terminal unit.
In response to this query, the SCP database will then query the associated mobile service provider terminal location register (Home or Visitor Location Register HLR/VLR) by using industry standard IS-41 Location Request messaging. Upon request, the mobile switching system will poll the mobile terminal unit to determine the activity and location of the mobile terminal unit. Once determined, the mobile system replies to the SCP database query with a Location.sub.-- Request return signal to report the mobile terminal unit's status. If the mobile unit is available, the mobile system returns the mobile's identification number to the SCP for call delivery routing to the identified mobile terminal unit. If the mobile system replies to the SCP database query indicating that the mobile terminal unit is unavailable, the wireline switching system will direct the terminating call delivery to the subscriber's wireline terminal unit.
While both known systems have been successful in providing call redirection of terminating wireline call delivery to the mobile terminal unit, the results have been less than satisfactory. Inefficiencies in these call delivery techniques have resulted in subscriber confusion, latent call delivery rates and limited mobile terminal portability outside the wireline and mobile home service area. Therefore, a need exits for a system and method for dynamically instructing the wireline system to redirect calls to the mobile terminal unit independent of the presence of an incoming call termination to the wireline terminal unit.